Celustka and Jack Colback have been ever-presents so far this season at full-back, but injuries and suspensions have meant that Modibo Diakite, Valentin Roberge and John O'Shea have all featured at different times in central defence.
So far, Sunderland have shipped 10 goals in their five league and cup matches, but Celustka thinks things will improve.
"There have been a lot of changes, but I can't say that I was more comfortable to play with one player than another," said the Czech, who is on Wearside on a season-long loan from Trabzonspor.
"Of course, when four defenders play together for a long time, there's a better connection between them.
"But in time, we'll get used to it and I hope we'll be better together."
Sunderland face West Brom on Saturday in a clash between the two bottom clubs in the league, and the only two without a win this season.
Celustka admits the game at the Hawthorns could be crucial, adding: "It's a key game for us, we are not in a good situation and neither are they.
"There is not such a big difference between teams at the bottom.
"We are still at the beginning of the season and if we won tomorrow, we could move up a lot of positions in the table.
"But of course everybody will be happier once we get that win. In every game, we've been close to getting a better result.
"I hope that luck will come to us and we get the result which we want because points count."